Field of Application
The present application relates to the field of liquid crystal display, and more particularly to a filament, ionization chamber, and ion-implantation apparatus.
Description of Prior Art
Display devices have become an indispensable part of modern life. In the process of low temperature polysilicon (LTPS) thin film transistors and organic light-emitting diodes (OLEDs) for display devices, the ion-implantation apparatus is needed to implant the plasma into the glass substrate. In the ion-implantation apparatus, the ion-source gas evenly enters in the ionization chamber through the air supply pipe, the filament of the ionization chamber filament generates hot electrons after supplying with current, the hot electrons and ion-source gas collide to each other to generate plasma.
In the conventional art, the filament in the ion-implantation apparatus needs to be bent several times to form a specific shape, so the filament has a smaller cross-sectional area at the bend points, causing the resistance of the bending points of the filament be larger than other portions which are un-bent. Hot electrons are generated after applying with current, the ion-source gas into ionization chamber collides the hot electrons to produce plasma, due to the portions of the filament which has larger resistance will produce more hot electrons, the more thermal electrons collide the ion-source gas to produce more plasma, resulting the plasma concentration around the bending points of the filament be higher, the plasma concentration near the filament is not uniform. The higher plasma concentration is easier to corrode the filament, so that the filament is more likely to break around the bending points after a long time usage, the filament life is shortened, the maintenance costs of ion-implantation apparatus and display equipment production costs is increased.